An electric power management system (for realizing Demand Response (DR)) is known in which a demand (request) for power saving is issued from an electric power company to an electric power management server (=an electric power management apparatus) in order to balance supply and demand of electric power. The electric power management server controls the equipment to manage in order to respond to the power saving demand. Rechargeable batteries are included in the equipment to manage. There is a case where the electricity accumulated in a rechargeable battery is used to meet the demand.
Rechargeable batteries may not be fully charged to prevent aging degradation. This makes it difficult to sufficiently exhibit the performance of the batteries when responding to the power saving demand.